title: Effects of non-steroidal aromatase inhibitor letrozole on sex inversion and spermatogenesis in yellow catfish Pelteobagrus fulvidraco.
abstract: The effects of letrozole (LZ), a potent nonsteroidal aromatase inhibitor (AI), on growth performance, sex inversion, and sex changes were investigated in yellow catfish (Pelteobagrus fulvidraco), which display sexual dimorphic growth. Growth performance was promoted significantly in the low-dose LZ treatment, compared with the control. Four LZ treatments produced dose-dependent male proportions that were significantly higher than that of the control. Histological examination of testes treated by LZ displayed a large amount of spermatozoa and enlarged lobule lumens, indicating that LZ treatments can potentially stimulate spermatogenesis. Changes of sex proportions 45 days after the end of the LZ treatments prove that the female germ cells possess a certain degree of bipotentiality. These results suggest that aromatase activity plays a vital role in sex differentiation, as in other teleosts, with inhibition of aromatase activity by AI bringing about sex inversion.
authors.affiliation: College of Fishery, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Shen
authors.forename: Qi-Xue
authors.initials: QX
authors.lastname: Fan
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Yun-Long
authors.initials: YL
authors.lastname: Zhang
authors.forename: Pei-Pei
authors.initials: PP
authors.lastname: Hu
authors.forename: Cong-Xin
authors.initials: CX
authors.lastname: Xie
mesh_terms: D000818:Animals; D047072:Aromatase Inhibitors / Q000494:pharmacology*; D002397:Catfishes / Q000254:growth & development / Q000502:physiology*; D005260:Female; D006066:Gonads / Q000033:anatomy & histology / Q000187:drug effects / Q000196:embryology; D000077289:Letrozole; D008297:Male; D009570:Nitriles / Q000494:pharmacology*; D010641:Phenotype; D012727:Sex Characteristics; D019849:Sex Determination Processes / Q000187:drug effects* / Q000502:physiology; D012744:Sex Ratio; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D000077289:Letrozole